How do I switch accounts under the NEW Google Drive Android API

Question

My authorization flow in the new Google Drive Android API is as follows:

1. Menu: SELECT ACCOUNT
2. connect();
3. onConnectionFailed() result.startRe

Answer 1

I realize I made quite a mess by opening two SO questions about essentially the same topic. So, it is a good time to consolidate the answers. I was searching for direct getter / setter methods in GDAA but found only the 'setter' - setAccountName()) - SO question 21583828 (actually did not, but Burcu helped me).

On the other side, 'getter' can be substituted by getting the account name from "onActivityResult()" - SO question 21501829

And yet another SO question - this one - on the same topic has been resolved as well.

So the conclusion is:

1. get account from 'onActivityResult()'
2. set account in 'setAccountName()'
3. keep your current account email around, so you can detect a new one (should user decide to switch) and reset Google Account Client if necessary.

UPDATE 2014-11-04:

Here is a wrapper that I use to persist and manage the Google accounts within my app.

import android.accounts.Account;
import android.accounts.AccountManager;
import android.content.Context;
import android.content.SharedPreferences;
import android.preference.PreferenceManager;
import com.google.android.gms.auth.GoogleAuthUtil;

public class GooAccMgr {
  private static final String ACC_NAME = "account_name";
  public  static final int FAIL = -1;
  public  static final int UNCHANGED =  0;
  public  static final int CHANGED = +1;

  private String mCurrEmail = null;  // cache locally

  public Account[] getAllAccnts(Context ctx) {
    return AccountManager.get(acx(ctx)).getAccountsByType(GoogleAuthUtil.GOOGLE_ACCOUNT_TYPE);
  }

  public Account getPrimaryAccnt(Context ctx) {
    Account[] accts = getAllAccnts(ctx);
    return accts == null || accts.length == 0 ? null : accts[0];
  }

  public Account getActiveAccnt(Context ctx) {
    return email2Accnt(ctx, getActiveEmail(ctx));
  }

  public String getActiveEmail(Context ctx) {
    if (mCurrEmail != null) {
      return mCurrEmail;
    }
    mCurrEmail = ctx == null ? null : pfs(ctx).getString(ACC_NAME, null);
    return mCurrEmail;
  }

  public Account email2Accnt(Context ctx, String emil) {
    if (emil != null) {
      Account[] accounts =
       AccountManager.get(acx(ctx)).getAccountsByType(GoogleAuthUtil.GOOGLE_ACCOUNT_TYPE);
      for (Account account : accounts) {
        if (emil.equalsIgnoreCase(account.name)) {
          return account;
        }
      }
    }
    return null;
  }

  /**
   * Stores a new email in persistent app storage, reporting result
   * @param ctx activity context
   * @param newEmail new email, optionally null
   * @return FAIL, CHANGED or UNCHANGED (based on the following table)
   * OLD    NEW   SAVED   RESULT
   * ERROR                FAIL
   * null   null  null    FAIL
   * null   new   new     CHANGED
   * old    null  old     UNCHANGED
   * old != new   new     CHANGED
   * old == new   new     UNCHANGED
   */
  public int setEmail(Context ctx, String newEmail) {
    int result = FAIL;  // 0  0

    String prevEmail = getActiveEmail(ctx);
    if        ((prevEmail == null) && (newEmail != null)) {
      result = CHANGED;
    } else if ((prevEmail != null) && (newEmail == null)) {
      result = UNCHANGED;
    } else if ((prevEmail != null) && (newEmail != null)) {
      result = prevEmail.equalsIgnoreCase(newEmail) ? UNCHANGED : CHANGED;
    }
    if (result == CHANGED) {
      mCurrEmail = newEmail;
      pfs(ctx).edit().putString(ACC_NAME, newEmail).apply();
    }
    return result;
  }

  private Context acx(Context ctx) {
    return ctx == null ? null : ctx.getApplicationContext();
  }
  private SharedPreferences pfs(Context ctx) {
    return ctx == null ? null : PreferenceManager.getDefaultSharedPreferences(acx(ctx));
  }
}

Hat-tip to Alex Lockwood for initial inspiration. Unfortunately, I can't find reference to his original code.